IBM said that the problem affects version 7 of its DB2 database for Linux. The company posted a patch, called FixPak 10a, on its Web site. IBM also is expected to update its usual DB2 version 7 technical support page with the latest fix.

The flaw was uncovered by Boston security company Core Security Technologies, which alerted IBM. Core Security Technologies plans to issue an alert on the vulnerability Thursday.

Engineers at the security company said the vulnerability, which could allow a person to get "root" privileges to a DB2 database, is simple to exploit. A company employee, for example, with only limited database access rights could trick the system into giving him or her access to the entire data store.

"This flaw is serious because it allows somebody to get control of a system...DB2 is a database, and we assume there is sensitive information in the database," said Paul Paget, CEO of Core Security Technologies.

The vulnerability allows a hacker to launch a "buffer overflow" attack by sending a long command to a file in the DB2 database which dictates access privileges, according to Core Security Technologies. With a buffer overflow, hackers can take control of a system and implant unwanted programs.